1. Field of the Invention
The present general inventive concept relates to an image forming apparatus. More particularly, the present general inventive concept relates to an apparatus and method to efficiently perform a printout irrespective of an insufficiency of colors contained in a toner or ink cartridge used in the image forming apparatus.
2. Description of the Related Art
Image-forming apparatuses print images provided from monitors, television sets (TVs) or other video output apparatuses. The monitors, TVs and other video output apparatuses use an RGB (Red, Green, Blue) color model, and the image forming apparatuses use a CMYK (Cyan, Magenta, Yellow, Black) color model. Hereinafter, particulars of the RGB color model and the CMYK color model will be explained.
The RGB color model is used in monitors, TVs and other video output apparatuses that implement colors by a principle of light. This color model represents colors based on the three primary colors of light, and has characteristics in that mixed colors become brighter than the colors before being mixed. Accordingly, a color representation by mixing the colors in the RGB color model is called an additive color mixture.
The CMYK color model is used in color printing. If colors are mixed in the CMYK color model, a tone of the mixed color becomes darker than the original colors. This kind of color mixture is called a subtractive color mixture. An operation of the image forming apparatus will be explained.
FIG. 1 is a block diagram illustrating a construction of a conventional image forming apparatus and a host computer.
Referring to FIG. 1, the image forming apparatus 100 includes a printing unit 102, a memory unit 104, a control unit 106, a storage unit 110, and a toner or ink cartridge unit 108. The host computer 120 includes an interface unit 122, a printer driver 124, a half-toning unit 130, a rendering unit 126, and a color matching unit 128
The printing unit 102 prints print data transferred from the control unit 106. The control unit 106 controls the components of the image forming apparatus 100 according to a control program. The memory unit 104 temporarily stores the print data which is transferred to the control unit 106 from the host computer 120, or stores information required to print the print data. The toner or ink cartridge unit 108 contains toner or ink for printing the print data. The storage unit 110 stores a residual amount of the toner or ink contained in the toner or ink cartridge unit. It will be apparent that the memory unit 104 and the storage unit 110 may be constructed into one device.
The interface unit 122 of the host computer 120 accesses to the image forming apparatus 100, and supports a communication interface between the host computer 120 and the image forming apparatus 100. The interface unit 122 may be implemented by an IEEE1284, USB, wireless, GPS or RS232C interface module or a network interface module. The interface unit 122 transmits the print data from the host computer 120, and provides the print data to the control unit 106 of the image forming apparatus 100. The printer driver 124 receives a print command to print a document (that is, print data) that a user has prepared using an application program, and transfers the print data to the rendering unit 126. The rendering unit 126 performs a rendering process for the transferred print data. The color matching unit 128 performs a color matching process for the print data for which the rendering process has been performed. The half-toning unit 130 performs a half-toning process for the print data for which the color matching process has been performed, and transfers the print data for which the color matching process has been performed to the interface unit 122.
FIG. 2 is a flowchart illustrating a conventional process of generating print data and transferring the generated print data from a host computer to an image forming apparatus. Hereinafter, with reference to FIG. 2, the conventional process of generating the print data that is performed by the host computer will be explained.
At step S200, the host computer receives a user's instructions to form an image of a specified document (print data). Generally, the user instructs the host computer to form the image using a keyboard. At step S202, the host computer performs a rendering process for the print data. At step S204, the host computer calculates a necessary amount of toner or ink of each color with respect to the rendered print data.
At step S206, the host computer compares the necessary amount of toner or ink of each color calculated at the step S204 with a stored amount of toner or ink of each color. At step S208, the host computer determines whether there is any color of which the stored amount of toner or ink is less than the necessary amount of toner or ink. If it is determined that there is any color of which the stored amount of toner or ink is less than the necessary amount of toner or ink, the host computer proceeds to step S210. If it is determined that there is no color of which the stored amount of toner or ink is less than the necessary amount of toner or ink, the host computer proceeds to step S212.
At the step S210, the host computer determines whether to continue the image forming process. If the host computer determines to continue the image forming process, it proceeds to the step S212, and, if the host computer determines not to continue, it proceeds to step S214. At the step S214, the host computer cancels the image forming process. At the step S212, the host computer performs color matching. At step S216, the host computer performs a half-toning process for the print data, and at step S218, the host computer transmits the print data to a spooler and temporarily stores the print data therein. At step S220, the image forming apparatus forms the image of the temporarily stored print data.
As described above, according to the conventional apparatus and method, the image forming is performed using only the remaining colors other than the color of which the amount of toner or ink is insufficient if the amount of toner or ink of any color necessary for the image forming of the print data is insufficient. Even if only a specified color is insufficient, a host computer displays a warning message that all of the colors are insufficient, and thus the user does not know which color is actually insufficient.